With a stronger than normal northeast monsoon affecting southern China during the month, Hong Kong's weather was colder than usual in December 2022. The monthly mean temperature was 16.6 degrees, 1.6 degrees below the normal figure of 18.2 degrees. The monthly total rainfall was 25.7 millimetres, about 11 per cent below the normal figure of 28.8mm. The annual total rainfall of 2 205.4mm in 2022 was about 9 per cent below the annual normal of 2 431.2mm.

     Under the influence of an intense northeast monsoon, the weather of Hong Kong was cloudy and rather cool on the first day of the month. The weather became brighter with a cool morning the next day. With the moderation of the northeast monsoon, there were sunny periods with warmer weather on December 3 and 4. The temperatures at the Observatory rose to 23.3 degrees on the afternoon of December 4, the highest of the month. Meanwhile, a replenishment of the northeast monsoon affected Guangdong later on December 4. Local weather turned mainly cloudy and cooler on December 5.

     Affected by a dry northeast monsoon, apart from cloudier weather on December 11, it was mainly fine and dry from December 6 to 12. Under the influence of the replenishment of the northeast monsoon and a broad band of rain-bearing clouds, the weather of Hong Kong became cloudy with a few rain patches from December 13 to 16. It was also cold on December 14 and 15. 

     An intense winter monsoon reached the coast of Guangdong on the night of December 16. With winds strengthening from the north and reaching gale force offshore and on high ground, local temperatures fell significantly on December 17. There was also some rain in that morning. The weather turned fine and very dry with cold mornings on December 18 and 19. The temperatures at the Observatory dropped to a minimum of 9.4 degrees on the morning of December 18, the lowest of the month. Dominated by a dry northeast monsoon, local weather remained fine from December 20 to 28. It was also very dry during the day from December 21 to 24. With the arrival of the replenishment of the northeast monsoon, the weather turned cloudier with a few light rain patches at first on December 29, before the return of fine and dry weather in the afternoon and the last two days of the month. It was also cold on the morning of December 31.

     One tropical cyclone occurred over the South China Sea and the western North Pacific in December 2022.

     Details of issuance and cancellation of various warnings/signals in December are summarised in Table 1. Monthly meteorological figures and departures from normal for December are tabulated in Table 2.

Ends/Wednesday, January 4, 2023
Issued at HKT 16:00

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